BEGIN;
BEGIN
EXPLAIN (ANALYZE, BUFFERS)
select
	100.00 * sum(case
		when p_type like 'PROMO%'
			then l_extendedprice * (1 - l_discount)
		else 0
	end) / sum(l_extendedprice * (1 - l_discount)) as promo_revenue
from
	lineitem,
	part
where
	l_partkey = p_partkey
	and l_shipdate >= date '1994-01-01'
	and l_shipdate < cast(date '1994-01-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1168068.21..1168068.22 rows=1 width=29) (actual time=8529.962..8529.963 rows=1 loops=1)
   Buffers: shared hit=311853 read=144168 dirtied=54 written=3687
   ->  Hash Join  (cost=101765.71..1154629.66 rows=767917 width=29) (actual time=2467.930..8134.895 rows=771125 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=311853 read=144168 dirtied=54 written=3687
         ->  Bitmap Heap Scan on lineitem  (cost=16243.71..1057588.90 rows=767917 width=12) (actual time=524.352..4871.484 rows=771125 loops=1)
               Recheck Cond: ((l_shipdate >= '1994-01-01'::date) AND (l_shipdate < '1994-02-01'::date))
               Heap Blocks: exact=413385
               Buffers: shared hit=278595 read=136901 dirtied=54 written=3149
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16051.74 rows=767917 width=0) (actual time=339.052..339.052 rows=775877 loops=1)
                     Index Cond: ((l_shipdate >= '1994-01-01'::date) AND (l_shipdate < '1994-02-01'::date))
                     Buffers: shared hit=111 read=2000 written=83
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1917.278..1917.278 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=33255 read=7267 written=538
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.019..1014.577 rows=2000000 loops=1)
                     Buffers: shared hit=33255 read=7267 written=538
 Planning time: 2.973 ms
 Execution time: 8537.833 ms
(19 rows)

COMMIT;
COMMIT